When Tom Coughlin describes Ryan Nassib, it’s not very exciting. But it is complimentary.

“He works at it,’’ the Giants coach said of the second-year quarterback. “He’s a worker, a grinder and doesn’t have a lot of emotion, whether it be good or bad.’’

This was a big summer for Nassib, trying to lock down the backup job after spending his rookie season at No. 3, behind Eli Manning and Curtis Painter. After what Coughlin called “a so-so game’’ by Nassib against the Steelers, Coughlin moved Painter ahead of Nassib and although no one came out and said it was a demotion, that’s clearly how Nassib viewed the move. And that’s clearly what it was.

“Just like anybody else at any other position, something like that will open your eyes a little bit,” Nassib said. “It was the coach’s decision. I still went out there every day and practiced as hard as I could, prepared as hard as I could, so if I got another shot I would be ready for it.”

Nassib rebounded and sparked the fourth-quarter comeback from a 26-0 deficit against the Colts and then, with Painter never getting onto the field, Nassib fired three touchdown passes to beat the Jets. The competition appears over heading into Thursday night’s preseason finale against the Patriots. Coughlin prefers to keep only two quarterbacks on the roster.

“I definitely feel like a different player than I did last year,” said Nassib, who starred at Syracuse and then was taken by the Giants in the fourth round of the 2013 NFL Draft. “It’s been a big jump from last year to this year.”

Mario Manningham is thrilled to be back in a Giants uniform but it is not likely he will get a chance to keep it on for much longer. After two years spent in San Francisco failing to live up to the expectations, Manningham re-signed with the Giants in March.

It hasn’t gone well. He sat out much of the spring workouts, did little to impress in training camp and in the preseason has only two receptions for 22 yards. Clearly, the torn ACL he suffered in 2012 and the additional surgery he needed last year robbed him of the quickness that highlighted his first four seasons with the Giants.

“He has had some spurts the last couple weeks where he has done some real good things on the practice field,’’ Coughlin said. “It hasn’t carried over to the game field yet. He will have another chance.’’

That last chance comes against the Patriots, the team Manningham helped beat in Super Bowl XLVI with his stirring sideline catch to spark the game-winning comeback.

Not that it matters much and not that anyone will remember, but the Giants are 4-0 in the preseason. The last time they went unbeaten in the preseason was 2006, when they went 4-0. The last (and only) time they finished 5-0 was 1985.